ACPI: ibm-acpi: Use a enum to select the thermal sensor reading strategy

This patch consolidades all decisions regarding the strategy to be used to
read thinkpad thermal sensors into a single enum, and refactors the
thermal sensor reading code to use a much more readable (and easier to
extend) switch() construct, in a separate function.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>

diff --git a/drivers/acpi/ibm_acpi.c b/drivers/acpi/ibm_acpi.c
index b81a95d2067c62f21c67cf849a25fbd040837d7f..baf9492f0a79859691f85d94b9e84bb9c0a56cd9 100644 (file)
--- a/drivers/acpi/ibm_acpi.c
+++ b/drivers/acpi/ibm_acpi.c
@@ -217,6 +217,17 @@ IBM_HANDLE(sfan, ec, "SFAN",       /* 570 */
 #define IBM_HKEY_HID   "IBM0068"
 #define IBM_PCI_HID    "PNP0A03"
 
+enum thermal_access_mode {
+       IBMACPI_THERMAL_NONE = 0,       /* No thermal support */
+       IBMACPI_THERMAL_ACPI_TMP07,     /* Use ACPI TMP0-7 */
+       IBMACPI_THERMAL_ACPI_UPDT,      /* Use ACPI TMP0-7 with UPDT */
+};
+
+#define IBMACPI_MAX_THERMAL_SENSORS 8  /* Max thermal sensors supported */
+struct ibm_thermal_sensors_struct {
+       s32 temp[IBMACPI_MAX_THERMAL_SENSORS];
+};
+
 struct ibm_struct {
        char *name;
        char param[32];
@@ -1275,50 +1286,79 @@ static int acpi_ec_write(int i, u8 v)
        return 1;
 }
 
-static int thermal_tmp_supported;
-static int thermal_updt_supported;
+static enum thermal_access_mode thermal_read_mode;
 
 static int thermal_init(void)
 {
-       /* temperatures not supported on 570, G4x, R30, R31, R32 */
-       thermal_tmp_supported = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
-
-       /* 600e/x, 770e, 770x */
-       thermal_updt_supported = acpi_evalf(ec_handle, NULL, "UPDT", "qv");
+       if (acpi_evalf(ec_handle, NULL, "TMP7", "qv")) {
+               if (acpi_evalf(ec_handle, NULL, "UPDT", "qv")) {
+                       /* 600e/x, 770e, 770x */
+                       thermal_read_mode = IBMACPI_THERMAL_ACPI_UPDT;
+               } else {
+                       /* Standard ACPI TMPx access, max 8 sensors */
+                       thermal_read_mode = IBMACPI_THERMAL_ACPI_TMP07;
+               }
+       } else {
+               /* temperatures not supported on 570, G4x, R30, R31, R32 */
+               thermal_read_mode = IBMACPI_THERMAL_NONE;
+       }
 
        return 0;
 }
 
-static int thermal_read(char *p)
+static int thermal_get_sensors(struct ibm_thermal_sensors_struct *s)
 {
-       int len = 0;
+       int i, t;
+       char tmpi[] = "TMPi";
 
-       if (!thermal_tmp_supported)
-               len += sprintf(p + len, "temperatures:\tnot supported\n");
-       else {
-               int i, t;
-               char tmpi[] = "TMPi";
-               s8 tmp[8];
+       if (!s)
+               return -EINVAL;
 
-               if (thermal_updt_supported)
-                       if (!acpi_evalf(ec_handle, NULL, "UPDT", "v"))
+       switch (thermal_read_mode) {
+       case IBMACPI_THERMAL_ACPI_UPDT:
+               if (!acpi_evalf(ec_handle, NULL, "UPDT", "v"))
+                       return -EIO;
+               for (i = 0; i < 8; i++) {
+                       tmpi[3] = '0' + i;
+                       if (!acpi_evalf(ec_handle, &t, tmpi, "d"))
                                return -EIO;
+                       s->temp[i] = (t - 2732) * 100;
+               }
+               return 8;
 
+       case IBMACPI_THERMAL_ACPI_TMP07:
                for (i = 0; i < 8; i++) {
                        tmpi[3] = '0' + i;
                        if (!acpi_evalf(ec_handle, &t, tmpi, "d"))
                                return -EIO;
-                       if (thermal_updt_supported)
-                               tmp[i] = (t - 2732 + 5) / 10;
-                       else
-                               tmp[i] = t;
+                       s->temp[i] = t * 1000;
                }
+               return 8;
 
-               len += sprintf(p + len,
-                              "temperatures:\t%d %d %d %d %d %d %d %d\n",
-                              tmp[0], tmp[1], tmp[2], tmp[3],
-                              tmp[4], tmp[5], tmp[6], tmp[7]);
+       case IBMACPI_THERMAL_NONE:
+       default:
+               return 0;
        }
+}
+
+static int thermal_read(char *p)
+{
+       int len = 0;
+       int n, i;
+       struct ibm_thermal_sensors_struct t;
+
+       n = thermal_get_sensors(&t);
+       if (unlikely(n < 0))
+               return n;
+
+       len += sprintf(p + len, "temperatures:\t");
+
+       if (n > 0) {
+               for (i = 0; i < (n - 1); i++)
+                       len += sprintf(p + len, "%d ", t.temp[i] / 1000);
+               len += sprintf(p + len, "%d\n", t.temp[i] / 1000);
+       } else
+               len += sprintf(p + len, "not supported\n");
 
        return len;
 }